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The MOND paradigm to the missing mass problem requires introducing a functional that is to be identified through observations and experiments. We consider AQUAL theory as a realization of the MOND. We show that the accurate value of the…

General Relativity and Quantum Cosmology · Physics 2013-06-28 Qasem Exirifard

Modified gravity (MOG) is a covariant, relativistic, alternative gravitational theory whose field equations are derived from an action that supplements the spacetime metric tensor with vector and scalar fields. Both gravitational (spin 2)…

General Relativity and Quantum Cosmology · Physics 2018-03-14 M. A. Green , J. W. Moffat , V. T. Toth

The works in this portfolio test the hypothesis that it is not possible to extrapolate the Newtonian inverse square law of gravity from Solar System to galaxy scales. In particular, I look into various tests of Modified Newtonian Dynamics…

Astrophysics of Galaxies · Physics 2023-09-26 Indranil Banik

Modified Newtonian dynamics (MOND) can be obtained by modifying the entropic formulation of gravity, this is achieved by considering the quantum statistical nature of the degrees of freedom on the holographic screen. Through this frame…

General Relativity and Quantum Cosmology · Physics 2013-05-27 Ehoud Pazy

Aims. We explore the dynamical friction on a test mass in gravitational systems in the Quasi linear formulation of Modified Newtonian Dynamics (QuMOND). Methods. Exploiting the quasi linearity of QuMOND we derive a simple expression for the…

Astrophysics of Galaxies · Physics 2024-09-11 Pierfrancesco Di Cintio , Federico Re , Caterina Chiari

Astronomical observations reveal a major deficiency in our understanding of physics $-$ the detectable mass is insufficient to explain the observed motions in a huge variety of systems given our current understanding of gravity, Einstein's…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-07 Indranil Banik , Hongsheng Zhao

The quantum field theory of gravitation is constructed in terms of Lagrangian density of Dirac fields which couple to the electromagnetic field $A_\mu$ as well as the gravitational field $\cal G$. The gravity appears in the mass term as $…

General Physics · Physics 2008-04-17 Takehisa Fujita

The stability of galaxies is either explained by the existence of dark matter or caused by a modification of Newtonian acceleration (MOND). Here we show that the modification of the Newtonian dynamics can equally well be obtained by a…

Astrophysics of Galaxies · Physics 2024-04-24 Søren Toxvaerd

We test Milgromian dynamics (MOND) using wide binary stars (WBs) with separations of $2-30$ kAU. Locally, the WB orbital velocity in MOND should exceed the Newtonian prediction by $\approx 20\%$ at asymptotically large separations given the…

Solar and Stellar Astrophysics · Physics 2024-09-06 Indranil Banik , Charalambos Pittordis , Will Sutherland , Benoit Famaey , Rodrigo Ibata , Steffen Mieske , Hongsheng Zhao

In the present contribution to the proceedings of MG17, the main aim is to elucidate the physically important effects of a special nonlinear gauge field with a square-root of the standard Maxwell Lagrangian in its action, interacting with a…

General Relativity and Quantum Cosmology · Physics 2024-10-16 Eduardo Guendelman , Emil Nissimov , Svetlana Pacheva

Globular clusters (GCs) in the Milky Way have characteristic velocity dispersions that are consistent with the predictions of Newtonian gravity, and may be at odds with Modified Newtonian Dynamics (MOND). We discuss a modified gravity (MOG)…

Astrophysics · Physics 2008-06-14 J. W. Moffat , V. T. Toth

Our modified gravity theory (MOG) is a gravitational theory without exotic dark matter, based on an action principle. MOG has been used successfully to model astrophysical phenomena such as galaxy rotation curves, galaxy cluster masses, and…

Cosmology and Nongalactic Astrophysics · Physics 2013-06-25 J. W. Moffat , V. T. Toth

We propose that there is a regime of quantum gravity phenomena, for the case that the cosmological constant is small and positive, which concerns phenomena at temperatures below the deSitter temperature, or length scales larger than the…

General Relativity and Quantum Cosmology · Physics 2017-11-01 Lee Smolin

A sample of 22 spiral galaxy rotation curves, measured in the 21 cm line of neutral hydrogen, is considered in the context of Milgrom's modified dynamics (MOND). Combined with the previous highly selected sample of Begeman et al. (1990),…

Astrophysics · Physics 2009-10-28 R. H. Sanders

Alternative theories of gravity have been recently studied in connection with their cosmological applications, both in the Palatini and in the metric formalism. The aim of this paper is to propose a theoretical framework (in the Palatini…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Gianluca Allemandi , Mauro Francaviglia , Matteo Luca Ruggiero , Angelo Tartaglia

After a succinct review of the MOND paradigm--with its phenomenology, and its various underlying theories--I concentrate on so called modified inertia (MI) formulations of MOND, which have so far received only little attention. These share…

Cosmology and Nongalactic Astrophysics · Physics 2011-11-30 Mordehai Milgrom

In this paper, we seek to find a modified theory of gravity that accounts for the back-reaction of QED on curved spacetime. It is already known that vacuum fluctuations induce interactions between gravity and photons. An effective action…

General Relativity and Quantum Cosmology · Physics 2017-08-30 Vyshnav Mohan

We report an updated constraint on the Solar System quadrupole parameter $Q_2$, which encodes the external field effect predicted by modified gravity versions of the MOND paradigm. Using the dataset employed to compute the DE440 planetary…

General Relativity and Quantum Cosmology · Physics 2026-02-24 R. S. Park , A. Hees , B. Famaey , H. Desmond , A. Durakovic

Any viable theory of modified Newtonian dynamcs (MOND) as modified gravity is likely to require fields in addition to the usual tensor field of General Relativity. For such theories the MOND phenomenology emerges from an effective fifth…

Astrophysics · Physics 2009-11-11 R. H. Sanders

We investigate particle laws of motion derived from nonstandard kinetic actions of a special form. We are guided by a phenomenological scheme--the modified dynamics (MOND)--that imputes the mass discrepancy observed in galactic systems to a…

Astrophysics · Physics 2008-11-26 M. Milgrom